Tractor



FIG. 1 is a top, front, left perspective view of a tractor embodying our new design;

FIG. 2 is a left side elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken line showing of portions of a tractor is included for the purpose of illustrating environmental use only and forms no part of the claimed design. 

CLAIM The ornamental design for a tractor, as shown and described. 